Let's take a look at a few of them...
The first Star Wars movie 'A New Hope' changed the sci-fi game forever when it hit theaters in 1977. If you still have a boxed Luke Skywalker figure from that point, you could find yourself $5,000 richer. That is, if you're willing to part ways with him.
Ah, Monopoly - the game that can end friendships and break families in half. If you have an early-edition Monopoly board, from the 1930s, it could go for serious money. It would also save future arguments if you got rid of it!
Every kid wanted one of these bad boys when they hit the shelves in the very late 80s. Nowadays, they can change hands for up to $2000 if still in working condition. There's a lot of money in retro video games!
Millennials of all ages will remember these things changing hands in the playground back in the day. 20 years later, not much has changed, but the value has gone way up.
Items from the first edition of cards can go for hundreds, even thousands of dollars. If you have a mint condition shiny Charizard, you're in the money.
Before Pokemon, there was Garbage Pail Kids, who also had their own collectible card sets. Check if you still have any in the attic, because if you have a decent-size collection, you could make thousands.
Most of us have fond memories of these candy dispensers, and they're highly sought-after by collectors as well. Rare limited edition Pez Dispensers, such as the Elvis one above, can go for over $300 online.
The original Game Boy hit shelves in 1989, and instantly engrossed an entire generation of young gamers. If you have an original working version, it could go for hundreds. Special editions as pictured above can go for thousands on eBay.
These were all the rage back in the day, and they're incredibly collectible now. Some original and prototype 1960s Hot Wheels cars, such as the 1969 “Volkswagen Beach Bomb” prototype, can go for up to $125,000!
These cute Pound Puppies were extremely popular with the kids back in the 80s. The first-edition Pound Puppies plush toys can go for $5,000! I mean, they're cute, but if I had one, it'd be on its way for the kind of money.
Depending on which Cabbage Patch doll you currently own from your past, you could potentially make a fortune. The Prosey family currently own over 5,000 dolls in their Maryland museum and is currently selling their entire collection for $360,000!
Fisher Price has been the go-to for years for all things children’s toys related. This 1936 toy is the stuff of legend for toy collectors, and if in good condition, can go for up to $3,000. How do people have this much money to spend on toys?!
I don't know about you, but I can't see a picture of Skeletor without hearing his dramatic evil laugh. A 1982 mint condition Skeletor action figure could see you laughing all the way to the bank, as they can easily go for at least $2,000.
Lite Brites have been around since the 1960s, and new versions of the toy are still being remade and revamped for modern kids. The original Lite Brite can go for up to $100, so have a look in the attic!
These things have been causing kids to pressure their parents into buying them Happy Meals for decades now. Certain toys are really valuable, such as early-2000s Disney character toys, which can go for up to $300.
These things were insanely popular in the late 90s, although they used to freak me out something fierce. An original, unopened box with a Furby inside can easily go for up to $900. This is a great chance to get rid of that creepy thing once and for all!
The Talkboy is a fancy version of a tape recorder that became popular after the release of the second Home Alone movie. If you still have one of these today, you could make over $200 by selling it online.
These things only cost a few bucks when they were new, but now collectors are willing to pay thousands of dollars for rare or limited edition Beanie Babies. A 1997 1st Edition Princess Diana Beanie Bear can sell for around $12,000!
I know this is a huge long shot, but if you’ve ever owned a 1934 Standard Gauge version of the train set, you may be sitting on a gold mine. This set is incredibly rare and sought-after, and as such, can go for a whopping $250,000.
The TMNT franchise has remained hugely popular since its 1980s heyday. Turtle action figures that are in mint condition can go for $600 a piece, but rare action figures can hit a price point of $5,000. Cowabunga!
Dolls have never really been my thing, but if you have an old collection, have a look for Sammy over here. If you still own the original Samantha Parkington doll, including all original accessories and outfits, you could make yourself a cool $4,000.